616565021 has 4 divisors (see below), whose sum is σ = 625767552. Its totient is φ = 607362492.

The previous prime is 616564997. The next prime is 616565039. The reversal of 616565021 is 120565616.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 616565021 - 2⁶ = 616564957 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (616565041) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4601165 + ... + 4601298.

It is an arithmetic number, because the mean of its divisors is an integer number (156441888).

Almost surely, 2^616565021 is an apocalyptic number.

It is an amenable number.

616565021 is a deficient number, since it is larger than the sum of its proper divisors (9202531).

616565021 is an equidigital number, since it uses as much as digits as its factorization.

616565021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9202530.

The product of its (nonzero) digits is 10800, while the sum is 32.

The square root of 616565021 is about 24830.7273554360. The cubic root of 616565021 is about 851.1242429423.

The spelling of 616565021 in words is "six hundred sixteen million, five hundred sixty-five thousand, twenty-one".